Repositório Colecção:http://hdl.handle.net/10400.18/86
Tue, 20 Mar 2018 01:56:52 GMT2018-03-20T01:56:52ZRegulation of glucose transporters by protein kinases in cancer cellshttp://hdl.handle.net/10400.18/5393
Título: Regulation of glucose transporters by protein kinases in cancer cells
Autor: Henriques, Andreia; Matos, Paulo; Jordan, Peter
Resumo: Background: Cancer cells require increased glucose supply to sustain proliferation. One mechanism involves increased expression of glucose transporter (GLUT) genes. But insulin has revealed that protein phosphorylation is another key mechanism in glucose uptake regulation: insulin binding to responsive cells triggers a signalling cascade with phosphorylation of TBC1D4, a negative regulator of endosomal GLUT trafficking, so that more transporters are inserted into the plasma membrane. Previous work from the host lab has identified the family of WNK protein kinases and shown that WNK1 can also phosphorylate TBC1D4 and promote GLUT translocation to the cell surface. Our objective is to understand the contribution of WNK1 to glucose uptake in colorectal cancer cells. Our objective is to understand the contribution of WNK1 to glucose uptake in colorectal cancer cells.
Descrição: Abstract publicado em: Ann Oncol. 2017 Sept;28(Suppl 5):50-52. doi:10.1093/annonc/mdx361.036.Fri, 01 Sep 2017 00:00:00 GMThttp://hdl.handle.net/10400.18/53932017-09-01T00:00:00ZInduced pluripotent stem cells as genetic disease modelshttp://hdl.handle.net/10400.18/5344
Título: Induced pluripotent stem cells as genetic disease models
Autor: Duarte, Ana Joana; Bragança, José; Amaral, Olga
Resumo: Lysosomal storage disorders (LSDs) are a group of genetic diseases characterised by lysosomal dysfunction. Some of the commonest LSDs are currently treated by enzyme replacement therapy. However, particularly in cases of advanced disease or late onset, results are discouraging. The lack of good ex vivo models hinders R&D and delays the understanding of the human pathophysiologic mechanisms. Thus, using iPSCs methods to generate the cell-targets to reproduce the disease, might help create ideal models for studying pathogenic mechanisms and to find new or more effective therapeutic strategies. iPSCs generated from somatic cells from patients are a necessary source for patient-specific studies since they maintain the patient’s genetic background.
Material and Methods: Using commercially obtained skin fibroblasts, as a control, guarantees better consistency in technical conditions. In this study we used two different methods to achieve forced expression of Oct4, Sox2, Klf4 and c-Myc: a non-integrative polycistronic plasmid vector and the Sendai virus method Transformation conditions with different vehicles of delivery were tested: different reagents, concentration ratios and timings were compared. Posterior validation of cells pluripotent state is currently underway.
Results: Fibroblasts are very difficult to transform but colonies were observed at around three weeks post-transfection using plasmid DNA. The Sendai virus method proved to be easier and faster.
Aims: Currently we are generating iPSCs from human skin fibroblasts and intend to obtain a good cellular model for LSDs.
Descrição: UniAlgarve and INSA collaboration under FCT project. Ana Joana Duarte is a PhD student at ICBAS-University of Porto.Mon, 01 May 2017 00:00:00 GMThttp://hdl.handle.net/10400.18/53442017-05-01T00:00:00ZGene editing in Lysosomal Diseaseshttp://hdl.handle.net/10400.18/5341
Título: Gene editing in Lysosomal Diseases
Autor: Duarte, Ana Joana; Bragança, José; Coutinho, Francisca; Amaral, Olga
Resumo: Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) were found as an immune adaptive mechanism in bacteria and quickly applied to various fields as a gene editing tool. Gene editing methods, as a research tool to attempt in vitro correction, have been carried out in several disorders. Induced pluripotent stem cells (iPSCs) from patients with several genetic diseases, including Lysosomal Storage Diseases (LSDs), have been successfully established. Patient-derived iPSCs present the advantage of having the patient’s genetic background with all corresponding influences on the disease’s mechanism. In LSDs, enzyme replacement therapy (ERT, regular supplementation of the defective enzyme), is the most common treatment to clear the accumulated substrates in patient cells but it is hardly effective in non-neurological disease forms. The CRISPR/Cas9 genome-editing system is most promising for the establishment of disease models and for the potential correction of causal. Gene editing technologies and iPSCs provide a unique system for data analysis and research for target therapy.Wed, 08 Nov 2017 00:00:00 GMThttp://hdl.handle.net/10400.18/53412017-11-08T00:00:00ZWhole-genome-based characterization of invasive Haemophilus influenzae isolates from a pre- and post-vaccine era in Portugalhttp://hdl.handle.net/10400.18/5267
Título: Whole-genome-based characterization of invasive Haemophilus influenzae isolates from a pre- and post-vaccine era in Portugal
Autor: Gonzalez Diaz, Aida; Pinto, Miguel; Bettencourt, Célia; Duarte, Silvia; Marti, Sara; Gomes, João Paulo; Bajanca-Lavado, Paula
Resumo: Introduction: Haemophilus influenzae (Hi) is responsible for severe invasive infections in both adults and children. Since the introduction in the year 2000 of the Hib vaccine, the incidence of disease has substantially declined, even though it doesn’t protect against non-typeable Hi (NTHi) isolates. Although not all NTHi are pathogenic, these are known to possess important virulence factors to promote colonization and host cells interactions, ultimately leading to disease. The application of WGS technology allows the uncovering of Hi population structure, including novel insights into its genomic features.
Aims: This study aims to fully characterize, by WGS, Hi isolates from a pre- and post-vaccine era, from 1992 to 2015, in Portugal.
Materials and Methods: Ninety invasive Hi isolates from the Portuguese NIH collection were selected for WGS. More than half were NTHi (63.3%) and 32.2% of the strains belong to a pre-vaccine era. Genomes were assembled and both sequence type (ST) and serotype were determined by PCR and confirmed in silico. A core-single nucleotide polymorphism-based phylogenetic tree was reconstructed to analyze overall genomic diversity between strains. Strains were further characterized by identifying the presence and genetic profile of genes related to antibiotic resistance and virulence factors, namely genes involved in adherence, host immune evasion, iron acquisition and lipooligosaccharides (LOS).
Results: Preliminary results show high ST heterogeneity among NTHi, contrasting with the homogeneity of ST for Hib strains (all ST6, except one). Core-SNP-based analysis revealed that all strains were distinguishable by more than 140,000 single nucleotide variant sites, with a highest genetic diversity observed between NTHi (overall ~35,000 nucleotide differences). Interestingly, although all Hib segregated together, the ST282 Hib strain possessed a distinct genome profile, diverging by ~17,200 nucleotide differences from ST6, while these overall diverged between them by ~2,480. Differential presence of important virulence factors was observed among strains, namely for hia/hsf, hmw1/hmw2, hap and iga, with distinct genomic profiles observed between strains, requiring in-depth analysis. Curiously, 90% of NTHi had the lgtA LOS-coding gene which was absent in all Hib. Additionally, five genes coding for other LOS were found to be simultaneously present or absent among NTHi strains, most belonging to a post-vaccine era, indicating a potential cluster of circulating strains.
Conclusions: Overall, we expect that the integrative analysis of all Hi isolates will strengthen the characterization of the genomic features in pre- and post-vaccine era, ultimately contributing to the understanding of the scenario of strains circulating in Portugal throughout more than 20 years.Fri, 01 Sep 2017 00:00:00 GMThttp://hdl.handle.net/10400.18/52672017-09-01T00:00:00ZA 669Kb deletion in 17q23.2, encompassing TBX2 and TBX4 genes, in a girl with a moderate developmental delay without any other pertinent abnormalityhttp://hdl.handle.net/10400.18/5259
Título: A 669Kb deletion in 17q23.2, encompassing TBX2 and TBX4 genes, in a girl with a moderate developmental delay without any other pertinent abnormality
Autor: Ferreira, Cristina; Marques, Bárbara; Pedro, Sónia; Serafim, Silvia; Amorim, Marta; Correia, Hildeberto
Resumo: Microdeletion of the 17q23.1-q23.2 region recently emerged as a syndrome (OMIM#613355) based in a small number of cases with a common phenotype including mild-to-moderate developmental delay, heart defects, microcephaly, postnatal grow retardation, and hand, foot, and limb abnormalities. All patients reported to date present mild to moderate developmental delay, in particular speech delay, and half of them hearing loss.
The smallest overlapping region has approximately 2.2 Mb and includes the transcription factors TBX2 and TBX4 genes. These genes have been implicated in a number of developmental pathways, including those of the heart and limbs. The TBX4 gene is also associated with the autosomal dominant small patella syndrome (SPS, OMIM 147891).
Here we report a 8 year-old girl with moderate developmental delay including learning disabilities. The test for Fragile X syndrome indicated an allele within the grey area (number of repeats ~50 CGG) inherited from her mother and probably not relevant.
Affymetrix Cytoscan HD chromosome microarray analysis was performed and a 669 Kb interstitial deletion was detected at 17q23.2 region, encompassing only five OMIM genes: BCAS3, TBX2, TBX4, NACA2 and BRIP1. To our knowledge this is the smallest deletion described in this region. None of the genes present in the deleted region are known to be associated with developmental problems.
We compare our patient with the other similar reported cases, in order to add some increased value to the phenotype-genotype correlation of deletions in this region.Mon, 01 May 2017 00:00:00 GMThttp://hdl.handle.net/10400.18/52592017-05-01T00:00:00Z